Debridement device and method

ABSTRACT

Devices, systems and methods for cutting and sealing of tissue such as bone and soft tissue. Devices, systems and methods include delivery of energy including bipolar radiofrequency energy for sealing tissue which may be concurrent with delivery of fluid to a targeted tissue site. Devices include debridement devices which may include a fluid source. Devices include inner and outer shafts coaxially maintained and having cutters for debridement of tissue. An inner shaft may include electrodes apart from the cutter to minimize trauma to tissue during sealing or hemostasis. Devices may include a single, thin liner or sheath for electrically isolating the inner and outer shafts.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 14/951,697, filed Nov. 25, 2015 and entitled “Debridement Device and Method” which is related to and claims the benefit of U.S. application Ser. No. 13/916,127, filed Jun. 12, 2013 and entitled “Debridement Device and Method” which is related to and claims the benefit of U.S. provisional application 61/658,724, filed Jun. 12, 2012 and of U.S. Provisional Application 61/704,904, filed Sep. 24, 2012, the entire disclosures of each of which are hereby incorporated by reference in their respective entireties.

BACKGROUND

The present invention is generally directed to devices, systems and methods for cutting and sealing tissue such as bone and soft tissue. The present invention may be particularly suitable for sinus applications and nasopharyngeal/laryngeal procedures and may combine or provide Transcollation® technology with a microdebrider device.

Devices, systems and methods according to the present disclosure may be suitable for a variety of procedures including ear, nose and throat (ENT) procedures, head and neck procedures, otology procedures, including otoneurologic procedures. The present disclosure may be suitable for a varient of other surgical procedures including mastoidectomies and mastoidotomies; nasopharyngeal and laryngeal procedures such as tonsillectomies, trachael procedures, adenoidectomies, laryngeal lesion removal, and polypectomies; for sinus procedures such as polypectomies, septoplasties, removals of septal spurs, anstrostomies, frontal sinus trephination and irrigation, frontal sinus opening, endoscopic DCR, correction of deviated septums and trans-sphenoidal procedures; rhinoplasty and removal of fatty tissue in the maxillary and mandibular regions of the face.

Sinus surgery is challenging due to its location to sensitive organs such as the eyes and brain, the relatively small size of the anatomy of interest to the surgeon, and the complexity of the typical procedures. Examples of debriders with mechanical cutting components are described in U.S. Pat. Nos. 5,685,838; 5,957,881 and 6,293,957. These devices are particularly successful for powered tissue cutting and removal during sinus surgery, but do not include any mechanism for sealing tissue to reduce the amount of bleeding from the procedure. Sealing tissue is especially desirable during sinus surgery which tends to be a complex and precision oriented practice.

Electrosurgical technology was introduced in the 1920's. In the late 1960's, isolated generator technology was introduced. In the late 1980's, the effect of RF lesion generation was well known. See e.g., Cosman et al., Radiofrequency lesion generation and its effect on tissue impedance, Applied Neurophysiology (1988) 51: 230-242. Radiofrequency ablation is successfully used in the treatment of unresectable solid tumors in the liver, lung, breast, kidney, adrenal glands, bone, and brain tissue. See e.g., Thanos et al., Image-Guided Radiofrequency Ablation of a Pancreatic Tumor with a New Triple Spiral-Shaped Electrode, Cardiovasc. Intervent. Radiol. (2010) 33:215-218.

The use of RF energy to ablate tumors or other tissue is known. See e.g., McGahan J P, Brock J M, Tesluk H et al., Hepatic ablation with use of radio-frequency electrocautery in the animal model. J Vasc Intery Radiol 1992; 3:291-297. Products capable of aggressive ablation can sometimes leave undesirable charring on tissue or stick to the tissue during a surgical procedure. Medical devices that combine mechanical cutting and an electrical component for cutting, ablating or coagulating tissue are described, for example, in U.S. Pat. Nos. 4,651,734 and 5,364,395.

Commercial medical devices that include monopolar ablation systems include the Invatec MIRAS RC, MIRAS TX and MIRAS LC systems previously available from Invatec of Italy. These systems included a probe, a grounding pad on the patient and a generator that provides energy in the range of 450 to 500 kHz. Other examples of RF bipolar ablation components for medical devices are disclosed in U.S. Pat. Nos. 5,366,446 and 5,697,536.

Medical devices are also used to ablate heart tissue with RF energy. See, e.g., Siefert et al. Radiofrequency Maze Ablation for Atrial Fibrillation, Circulation 90(4): I-594. Some patents describing RF ablation of heart tissue include U.S. Pat. Nos. 5,897,553, 6,063,081 and 6,165,174. Devices for RF ablation of cardiac tissue are typically much less aggressive than RF used to cut tissue as in many procedures on cardiac tissue, a surgeon only seeks to kill tissue instead of cutting or removing the tissue. Cardiac ablation of this type seeks to preserve the structural integrity of the cardiac tissue, but destroy the tissue's ability to transfer aberrant electrical signals that can disrupt the normal function of the heart.

Transcollation® technology, for example, the sealing energy supplied by the Aquamantys® System (available from Medtronic Advanced Energy of Portsmouth, N.H.) is a patented technology which stops bleeding and reduces blood loss during and after surgery and is a combination of radiofrequency (RF) energy and saline that provides hemostatic sealing of soft tissue and bone and may lower transfusion rates and reduce the need for other blood management products during or after surgery. Transcollation® technology integrates RF energy and saline to deliver controlled thermal energy to tissue. Coupling of saline and RF energy allows a device temperature to stay in a range which produces a tissue effect without the associated charring found in other ablation methods.

Other ablation devices include both mechanical cutting as well as ablation energy. For example, the PK Diego® powered dissector is commercially available from Gyms ENT of Bartlett, Tenn. This device utilizes two mechanical cutting blade components that are moveable relative to each other, one of which acts as an electrode in a bipolar ablation system. The distal end portion of the device includes six layers to accomplish mechanical cutting and electrical coagulation. The dual use of one of the components as both a mechanical, oscillating cutting element and a portion of the bipolar system of the device is problematic for several reasons. First, the arrangement exposes the sharp mechanical cutting component to tissue just when hemostasis is sought. In addition, the electrode arrangement does not provide for optimal application of energy for hemostasis since the energy is applied essentially at a perimeter or outer edge of a cut tissue area rather than being applied to a central location of the cut tissue. The arrangement of the device also requires more layers than necessary in the construction of a device with both sharp cutters and RF ablation features. The overabundance of layers can make it difficult to design a small or optimally-sized distal end. Generally speaking, the larger the distal end, the more difficult it is for the surgeon to visualize the working surfaces of the device. The use of six layers at the distal end of the system also interferes with close intimate contact between the tissue and the electrodes. Some examples of cutting devices are described in U.S. Pat. Nos. 7,854,736 and 7,674,263.

The Medtronic Straightshot® M4 Microdebrider uses sharp cutters to cut tissue, and suction to withdraw tissue. While tissue debridement with the Medtronic microdebrider system is a simple and safe technique, some bleeding may occur. The Medtronic microdebrider does not include a feature dedicated to promoting hemostasis or bleeding management. Thus, nasal packing is often used.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, where like numerals refer to like components throughout several views:

FIG. 1 is a perspective view of a system according to one aspect of the present invention;

FIG. 2 is a perspective view of a distal end region of a device with an inner shaft in a position according to one aspect of the present invention;

FIG. 3 is a perspective view of the distal end region of a device with an inner shaft in an alternative position according to one aspect of the present invention;

FIG. 4 is a perspective view the distal end region of FIG. 2 with an outer shaft removed to show portions of an inner shaft and insulation liner;

FIG. 5 is a perspective view of the distal end region of FIG. 4 with the insulation liner removed to show additional portions of the inner shaft and electrode traces;

FIG. 6 is a perspective view of the distal end region of FIG. 5 with the electrode traces removed;

FIG. 7 is a perspective view of the distal end region of FIG. 6 with components removed;

FIG. 8 is a perspective view of another embodiment of a distal end portion of an outer shaft of a device according the present invention;

FIG. 9 is a perspective view the outer shaft of FIG. 8 showing a partial electrode configuration according to an aspect of the present invention;

FIG. 10 is a perspective view of a proximal end of an inner shaft according to an aspect of the present invention;

FIG. 11 is a perspective view of a proximal end of a device showing a button activation cell according to an aspect of the present invention;

FIG. 12 is a an exploded view of the button activation cell of FIG. 11 according to an embodiment of the present invention;

FIG. 13 is a perspective view of portions of the button activation cell of FIG. 11 according to an aspect of the present invention;

FIG. 14 is a perspective view of the assembly of FIG. 13 with portions removed according to an aspect of the present invention;

FIG. 15 is a top view of the button activation cell of FIG. 10 according to an aspect of the present invention.

DETAILED DESCRIPTION

FIG. 1 illustrates a system 10 according to an aspect of the present invention. The system 10 includes a device 100 having a distal end region indicated generally at 120 and a proximal end region indicated generally at 110. The device includes an outer shaft 130 and an inner shaft 140 coaxially maintained within the outer shaft 130. A portion of the inner shaft 140 is shown in FIG. 1 at distal end region 120. Proximal end region 110 includes a button activation cell 200 comprising a housing 204 and a button 202, the proximal end region further comprising a hub 175 coupled to inner shaft 140. The hub is configured to couple to a handle or handpiece 177 which can be manipulated by a user (e.g., a surgeon). The handpiece 177, in turn may be coupled to an integrated power console or IPC 179 for driving the device 100 and specifically for controlling rotation of inner shaft 140. The IPC 179 may also include a fluid source (not shown) and may provide fluid delivery to device 100.

Proximal end region 110 also includes a fluid source connector 150, a power source connector 160 and a suction source connector 170 for connection to a fluid source 152, a power source, 162 and/or a suction source of system 10. One fluid useful with the present disclosure is saline, however, other fluids are contemplated. Power source 162 may be a generator and optionally may be designed for use with bipolar energy or a bipolar energy supply. For example, the Transcollation® sealing energy supplied by the Aquamantys® System (available from Medtronic Advanced Energy of Portsmouth, N.H.) may be used. Both the fluid source 152 and suction source 172 are optional components of system 10. However, use of fluid in conjunction with energy delivery aids in providing optimal tissue effect as will be further explained, thus embodiments of the present invention include specific arrangement of the device 100 for coupling of energy with a fluid. In use, a fluid (e.g., saline) may be emitted from an opening at the distal end region of the device 100. Tissue fragments and fluids can be removed from a surgical site through an opening (not shown in FIG. 1 ) in the distal end region via the suction source 172, as will be further explained below.

FIG. 2 shows an enlarged perspective view of distal end portion 120 of device 100. The outer shaft 130 includes a window or opening 134 at a distal end 135 of the outer shaft 135. Window 134 is defined by an outer shaft cutting edge or cutter 132, which comprises cutting teeth 133. The outer shaft 130 may be rigid or malleable or combinations thereof and may be made of a variety of metals and/or polymers or combinations thereof, for example may be made of stainless steel. A distal portion 148 of the inner shaft 140 can be seen through the window or opening 134 of outer shaft 130. In FIG. 1 , inner shaft 140 is depicted in a position such that an inner shaft cutting edge or cutter 141 (FIG. 3 ), comprising cutting teeth 143 is facing an inner wall (not shown) of outer shaft 130. Cutter 141 defines an inner shaft window or opening 154 (FIG. 3 ).

Outer and inner shaft cutters 132 and 141 may move relative to one another in oscillation or rotation (or both) in order to mechanically cut tissue. For example, outer shaft cutter 132 may remain stationary relative to the hub 175 and button assembly 200 while the inner shaft cutter 141 may rotate about a longitudinal axis A of the device, thereby cutting tissue.

Rotation of inner shaft 140 may be achieved via manipulation of hub 175 (FIG. 1 ). that can orient the inner shaft 140 relative to the outer shaft 130 and may additionally allow for locking of the inner shaft relative to the outer shaft in a desired position, i.e., inner shaft may be locked in position when cutter 141 is facing down and electrode assembly 142 is facing up. As described above, hub 175 may be connected to a handle or handpiece 177 which may be controlled by an IPC 179. Alternatively, the hub 175 and/or handle portions may be manipulated manually. Inner shaft 140 may be selectively rotated to expose an electrode assembly 142 comprising electrodes 142 a, 142 b, through opening 134 of outer shaft 130, as shown in FIG. 2 . Electrodes 142 a, 142 b may comprise electrode traces and the electrode traces may extend from the distal portion 148 of the inner shaft to a proximal end 151 (FIG. 10 ) of the inner shaft 140. As depicted in FIG. 2 , inner shaft 140 is positioned such that the inner shaft cutter 141 is facing the interior (not shown) of outer shaft 130 and may be said to be in a downward facing direction and comprise a downward position. In the downward position, tissue is shielded from the inner shaft cutter 141 during hemostasis (via energy delivery through electrodes 142 a, 142 b), thereby delivering energy to tissue with no attendant risk that the cutting teeth 143 of the inner shaft 140 will diminish the efforts to achieve hemostasis. Device 100 may thus comprise two modes: a cutting or debridement mode and a sealing or hemostasis mode and the two modes may be mutually exclusive, i.e. hemostasis is achieved via energy delivery to tissue while cutters 132, 141 are not active or cutting. As described below, energy may be advantageously delivered simultaneously with a fluid such as saline to achieve an optimal tissue effect by delivering controlled thermal energy to tissue.

As depicted in FIG. 3 , when the inner shaft 140 is oriented such that the cutter 141 is in the downward position, rotating inner shaft 140 approximately 180 degrees relative to the outer shaft 130 will expose inner shaft cutter 141 and inner shaft opening 154 through the outer shaft opening 134. When the inner shaft cutter 141 is positioned as shown in FIG. 3 , the inner shaft cutter 141 may be said to be in an upward position. The inner shaft opening 154 is fluidly connected to an inner shaft lumen 156, a portion of which can be seen in FIG. 7 . Lumen 156 extends from the inner shaft distal portion 148 to the proximal end 151 (FIG. 10 ) of inner shaft 140 and may be fluidly connected with the suction source 172. With this configuration, tissue cut via inner and outer shaft cutters 141, 132 may be aspirated into the inner shaft lumen 156 through the inner shaft opening 154 upon application of suction source 172, thereby removing tissue from a target site.

With reference between FIGS. 4 and 5 , the inner shaft 140 comprises a proximal assembly 168 including a proximal assembly shaft component 169 (more clearly seen in FIG. 5 ) and electrodes 142 a and 142 b. Inner shaft 140 also includes a joining assembly 144, which may be a non-conductive component and more specifically may comprise a liquid crystal polymer (LCP) overmold assembly. The joining assembly 144 may effectively join or connect the distal portion 148 of inner shaft 140 with the proximal assembly shaft component 169 (most clearly depicted in FIG. 5 ). Joining assembly 144 includes an extension portion 146 which aids in minimizing arc tracking from the electrodes 142 a and 142 b as will be further elucidated in the following discussion.

Electrodes or electrode traces 142 a and 142 b comprise bipolar electrodes and may comprise wet or dry electrodes. Electrodes 142 a and 142 b may be used to deliver any suitable energy for purposes of coagulation, hemostasis or sealing of tissue. Electrodes 142 a and 142 b are particularly useful with fluid such as saline provided by fluid source 152 (FIG. 1 ) which may be emitted near the outer shaft opening 134. Outer shaft opening 134 is fluidly connected to an outer shaft lumen 136, shown in phantom in FIG. 7 . Lumen 136 extends from outer shaft opening 134 to the proximal end region 110 of device 100 and may be fluidly connected to the fluid source 152 (FIG. 1 ). Thus, fluid can be delivered to the opening 134 of outer shaft 130 and interacts with electrode traces 142 a, 142 b, as will be further described with reference to FIG. 1 . In this manner, electrode traces 142 a and 142 b can advantageously provide Transcollation® sealing of tissue when used with the Transcollation® sealing energy supplied by the Aquamantys System, available from the Advanced Energy Division of Medtronic, Inc. With respect to “wet” RF coagulation technology, the technology for sealing tissue described in U.S. Pat. Nos. 6,558,385; 6,702,810, 6,953,461; 7,115,139, 7,311,708; 7,537,595; 7,645,277; 7,811,282; 7,998,140; 8,048,070; 8,083,736; and 8,361,068 (the entire contents of each of which is incorporated by reference) describe bipolar coagulation systems believed suitable for use in the present invention. Other systems for providing a source of energy are also contemplated.

Both FIGS. 4 and 5 depict the distal end region 120 of device 100, with outer shaft 130 removed. FIG. 4 shows a portion of the inner shaft 140 coaxially maintained in an insulation liner or sheath 180. The liner 180 may extend from a location proximal the inner shaft cutter 141 and cutting teeth 143, along inner shaft 140, to the proximal end 151 of inner shaft 140. Liner 180 provides insulation between the inner and outer shafts 130, 140, thus providing electrical isolation of the electrodes 142 a and 142 b from outer shaft 130 as well as from one another while only adding a single, very thin layer to the overall device 100. Liner 180 may be made of any suitable material, for example, fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), or any other material suitable as a non-conductive or electrically insulative material. Regardless, liner 180 is constructed so as to be negligible in its contribution to the overall diameter of the device 100 and particularly the distal end region 120 of the device 100.

FIG. 5 shows the distal end region 120 of device 100 with both the outer shaft 130 and the insulation liner 180 removed, thus exposing only portions of inner shaft 140. As described above, inner shaft 140 includes a distal portion 148, which includes cutter 141, and an inner shaft proximal assembly 168 including proximal assembly shaft component 169. The individual distal portion 148 and shaft component 169 can be seen more clearly in FIG. 7 in which the joining assembly 144 and electrodes 142 a, 142 b are removed. The proximal assembly shaft component 169 may comprise a variety of suitable materials and for example, may comprise a liquid crystal polymer (LCP) extruded shaft component that is configured to support the placement of metallized conductors (e.g., electrodes 142 a, 142 b) and may support overmolding (e.g. of joining assembly 144) and/or a plating process, such as described below. Proximal assembly shaft component 169 may undergo a laser etching process to form the depressed areas 145 suitable for electrode placement or plating. Other methods of forming the depressed areas 145 are also contemplated. FIG. 6 shows inner shaft 140 with the electrodes or electrode traces 142 a, 142 b removed from the proximal portion 168 and joining assembly 144. Electrodes 142 a and 142 b may be formed on the proximal assembly shaft component 169 and on a portion of joining assembly 144 in a plating process for forming electrode traces. The portion over which the electrode traces may be applied includes depressed areas 145 (FIG. 6 ), which may be laser etched areas. One process of electrode plating may include first applying copper sufficient to conduct the desired power and then adding nickel and gold layers to the laser etched area 145. Other metals and combinations of metals are also contemplated, for example, silver may be used or any other metal or combination of metals effective in providing a cross section which meets power requirements for the energy delivery. Regardless, the plating process and overall electrode 142 a, 142 b thickness or depth is configured such that the electrodes 142 a, 142 b do not negatively impact the diameter of the device 100. As but one example, the electrode plating process may result in a dimensional change to the overall diameter as little as 0.0015″.

FIG. 5 also more fully depicts joining assembly 144 which joins the distal portion 148 with the inner shaft proximal assembly 168 of the inner shaft 140. As seen in FIG. 5 , portions of distal portion 148 and proximal assembly shaft component 169 may be configured in a “puzzle piece” arrangement as is indicated at joining assembly 144 which follows the lines of the puzzle piece. Each of the distal portion 148 and proximal assembly shaft component 169 include a mating edge 192, 190, respectively. This configuration distributes forces acting on the inner shaft 140 when the device 100 is in a cutting mode to aid in a secure coupling of the distal portion 148 and shaft component 169. The joining assembly extension portion 146 is located between electrodes 146 a and 146 b. This extension portion 146 provides adequate space between the electrodes 146 a, 146 b to mitigate arc tracking between the two and to improve the tissue depth effect.

Returning to FIG. 1 , when fluid from fluid source 152 is provided through lumen 136 of the outer shaft 130, the fluid may travel between the outside diameter of the inner shaft 140 and the inside diameter of the outer shaft 130 to the distal end 120 of device 100. Fluid travels distally down the lumen 136 of outer shaft 130 and may “pool” in an area shown in FIG. 1 as essentially defined by the opening 134 of outer shaft 130. Likewise, electrodes 142 a and 142 b may be located slightly below the surface of the joining assembly 144 and/or the inner shaft proximal portion 168 (FIGS. 4, 5 ), creating another area for fluid pooling. This depressed electrode 142 a, 142 b surface can also prevent wear of the electrodes 142 a, 142 b. Pooling of fluid at the electrodes 142 a, 142 b allows for effective interaction between the fluid and the electrodes which in turn can provide effective and advantageous sealing of tissue, and in particular may provide effective Transcollation® sealing of tissue.

With continued reference to FIG. 1 , electrodes 142 a and 142 b are situated in an area generally centrally located with respect to the outer shaft opening 134 when inner shaft cutter 141 is in a downward position. This generally central location of the electrodes 142 a, 142 b allows for energy delivery at an optimal point of debridement. In other words, after inner shaft cutter 141 and outer shaft cutter 132 are rotated or oscillated relative to one another to cut tissue, rotating inner shaft cutter 141 to the downward position to expose electrodes 142 a, 142 b and deliver energy through the electrodes 142 a, 142 b may allow for hemostasis in an area generally central to where debridement or cutting of tissue had taken place. The generally centered electrodes 142 a, 142 b allow for energy to essentially travel or radiate outwardly from the electrodes 142 a, 142 b to coagulate the approximately the entire area of tissue previously cut. In other words, energy, and particularly RF energy may be provided at the center or near center of a portion of tissue previously cut or debrided.

FIGS. 8 and 9 depict an alternative outer shaft 130 and inner shaft 140 whereby an outer shaft window or opening 134 a is essentially enlarged as compared to outer shaft window 134 (FIG. 2 ) via a proximal window portion 138. This enlarged opening 134 a may afford an inner shaft 140 having significantly larger electrodes 142 c, 142 d, such as depicted in FIG. 9 . Electrodes 142 c, 142 d may be otherwise constructed similar to electrodes 142 a and 142 b (e.g., FIG. 2 ) and the remaining portions of inner shaft 140 may be constructed as described above.

FIG. 10 depicts a section of proximal assembly 168 of inner shaft 140 which section, when assembled in device 100, is generally situated within button activation assembly 200 (FIG. 1 ). Electrodes 142 a and 142 b are shown as individual traces separated by proximal assembly shaft component 169, which isolates the electrode traces 142 a, 142 b from one another. Electrodes 142 a includes a proximal portion comprising a partial ring 300 extending at least partially circumferentially around proximal assembly shaft component 169. Likewise electrode 142 b comprises a proximal portion comprising a ring 301 which may extend fully circumferentially around proximal assembly shaft component 169 as depicted in FIG. 10 . Rings 300 and 301 provide contact surface area for electrical contacts such as clips 216 a, 216 b (FIGS. 12, 14 ).

FIGS. 11-14 depict the button activation assembly 200 and the way in which energy provided to electrodes 142 a, 142 b. FIG. 11 shows a partial cutaway view of the button activation assembly 200 one housing half 204 b (FIG. 12 ) removed such that only housing half 204 a is shown leaving portions of the button activation assembly 200 exposed. As shown in FIG. 11 , at the proximal end region 110 of device 100 is provided a fluid housing 156 connected to the fluid connector 150 and an electrical contact housing 210 connected to the power source connector 160. The power source connector 160 is in turn coupled to a power cord or cable 161 comprising wires 161 a, 161 b and 161 c. Power cord 161 is coupled to a printed circuit board (PCB) 206 via wires 161 a, 161 b and 161 c. In addition, electrical contacts 164 and 166 electrically couple the power cord to caps 208 a and 208 b, as further explained with reference top FIGS. 12-14 .

FIG. 12 shows and exploded view of the button activation cell 200 of FIG. 11 as well as a portion of proximal end region 110 with portions of the button activation cell removed. FIG. 13 shows an enlarged view of the portion of proximal end region 110 shown in FIG. 13 with still further portions removed. With reference between FIGS. 12-14 , FIG. 12 shows two housing halves 204 a and 204 b which may be attached via any attachment device such as screws 400 and may, as described above, house various components of the button activation cell 200 as well as the fluid housing, electrical contact housing 210 and clip housing 220. Also depicted in FIG. 12 are o-rings 158 a, 15 b are adjacent fluid housing 156 and an o-ring 228 which is adjacent housing 220 for sealing fluid from the various components, including the electrical components provided in electrical contact housing 210.

Clip housing 220, shown alone or apart from cell 200 in FIG. 12 , comprises two windows 224 a, 224 b. Clips 216 a and 216 b are provided in windows 224 a, 224 b with a flag 218 a, 218 b of each clip 216 a and 216 b viewable through or adjacent to windows 224 a, 224 b, such as depicted in assembled form in FIG. 13 . Attached to clip housing 220 are two retaining rings 222 a, 222 b, for retaining the clips 216 a and 216 b in housing 220. As best seen in FIG. 14 , post connectors 214 a, 214 b are coupled to clip flags 218 a, 218 b and provided on post connectors 214 a, 214 b are springs 212 a, 212 b. Over post connectors 214 a, 214 b and springs 212 a, 212 b are provided caps 208 a, 208 b. Also as best seen in FIG. 14 , clips 216 a and 216 b are coupled to an in contact with rings 300 and 301 respectively of electrode traces 142 a, 142 b. Clips 216 a, 216 b, post connectors 214 a,b, springs 212 a, 212 b and caps 208 a, 208 b are made of an electrically conductive material and provide electrical contact of the caps 208 a, 208 b to rings 300 and 301 when a source of power is activated or applied at caps 208 a, 208 b. As seen in FIGS. 11 and 12 , the caps 208 a, 208 b are provided under the PCB 206, over which is provided button 202. Depressing button 202 drives a button contact assembly 203 which in turn moves to close circuitry of the PCB 206 allowing a pathway for current to flow from the power source 162 thus providing power to the electrodes 142 a, 142 b through the clips 216 a, 216 b as described above.

When energy is activated or applied to clips 216 a, 216 b, due to the intimate contact of clips 216 a and 216 b with electrode rings 300 and 301, electrical communication with bipolar electrodes 142 a, 142 b is achieved whereby energy is delivered along electrode traces 142 a and 142 b to the distal end 120 of device 100 and is applied to a targeted area of tissue as described herein above. This aspect of the present disclosure integrates electrodes 142 a and 142 b to the inner shaft 140 while isolating the inner shaft and electrodes 142 a and 142 b from other components and while distributing the required power to two separate and distinct electrodes 142 a, 142 b. This design also minimizes the number of layers required to make the distal end 120 of the device.

FIG. 15 is a top view of the button activation assembly 200 and depicts an alignment fiducial 420 through a window 430 in housing 204. Alignment fiducial 420 is provided on housing 221 (FIG. 13 ). The alignment fiducial 420 is one of two fiducials which may be provided on device 100, with the second fiducial not shown. Alignment fiducials (e.g., 420) are provided as indicators of alignment of inner cutter 141 and may be colored to indicate a particular alignment configuration.

Various modifications and alterations to this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure. It should be understood that this disclosure is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the disclosure intended to be limited only by the claims set forth herein as follows. 

What is claimed is:
 1. A bipolar electrosurgical debridement device, comprising: an outer shaft defining a lumen, a distal portion, and a window at the distal portion; an inner shaft rotatably disposed within the lumen and defining a distal end portion forming a cutting window configured to be selectively exposed at the window of the outer shaft upon rotation of the inner shaft relative to the outer shaft; a handle coupled to the inner and outer shafts; a clip housing disposed within the handle and defining a longitudinal lumen configured to receive a proximal end portion of the inner shaft therethrough, the clip housing defining a first window axially spaced from a second window along a longitudinal axis defined by the inner shaft; a first electrode disposed on the inner shaft and having a proximal end portion removably connected to a first clip disposed within the clip housing and a distal end portion configured to be selectively exposed through the window of the outer shaft; a second electrode disposed on the inner shaft and electrically isolated from the first electrode, the second electrode having a proximal end portion removably connected to a second clip disposed within the clip housing and a distal end portion configured to be selectively exposed through the window of the outer shaft, wherein at least a portion of the first clip is exposed through the first window of the clip housing and at least a portion of the second clip is exposed through the second window of the clip housing; and a button assembly coupled to the housing and including a single actuator operably coupled to the exposed portions of the first and second clips, wherein movement of the single actuator to an activation position is configured to simultaneously complete an electrical pathway between the first clip and a power source and the second clip and the power source such that power is delivered from the power source simultaneously to the first and second electrodes.
 2. The bipolar electrosurgical debridement device of claim 1, wherein the actuator is a button.
 3. The bipolar electrosurgical debridement device of claim 2, wherein the button assembly further includes a biasing member connected to the button for biasing the button away from the activation position.
 4. The bipolar electrosurgical debridement device of claim 2, wherein the button assembly further includes a printed circuit board electrically coupled to the first and second clips.
 5. The bipolar electrosurgical debridement device of claim 1, wherein the proximal end portion of each of the first and second electrodes is a partial ring electrode.
 6. The bipolar electrosurgical debridement device of claim 1, further comprising a fluid passage formed between the outer and inner shafts for receiving a fluid.
 7. A bipolar electrosurgical system, comprising: a power source; and a bipolar electrosurgical debridement device comprising: an outer shaft defining a lumen, a distal portion and a window at the distal portion; an inner shaft rotatably disposed within the lumen and defining a distal end portion forming a cutting window configured to be selectively exposed at the window of the outer shaft upon rotation of the inner shaft relative to the outer shaft; a handle coupled to the inner and outer shafts; a clip housing disposed within the handle and defining a longitudinal lumen configured to receive a proximal end portion of the inner shaft therethrough, the clip housing defining a first window axially spaced from a second window along a longitudinal axis defined by the inner shaft; a first electrode disposed on the inner shaft and having a proximal end portion removably connected to a first clip disposed within the handle clip housing and a distal end portion configured to be selectively exposed through the window of the outer shaft; a second electrode disposed on the inner shaft and electrically isolated from the first electrode, the second electrode having a proximal end portion removably connected to a second clip disposed within the clip housing and a distal end portion configured to be selectively exposed through the window of the outer shaft, wherein at least a portion of the first clip is exposed through the first window of the clip housing and at least a portion of the second clip is exposed through the second window of the clip housing; and a button assembly coupled to the housing and including a single actuator operably coupled to the exposed portions of the first and second clips, wherein movement of the single actuator to an activation position is configured to simultaneously complete an electrical pathway between the first clip and a power source and the second clip and the power source such that power is delivered from the power source simultaneously to the first and second electrodes.
 8. The bipolar electrosurgical debridement system of claim 7, wherein the actuator is a button.
 9. The bipolar electrosurgical debridement system of claim 8, wherein the button assembly further includes a biasing member connected to the button for biasing the button away from the activation position.
 10. The bipolar electrosurgical debridement system of claim 8, wherein the button assembly further includes a printed circuit board electrically coupled to the first and second clips.
 11. The bipolar electrosurgical debridement system of claim 7, wherein the proximal end portion of each of the first and second electrodes is a partial ring electrode.
 12. The bipolar electrosurgical debridement system of claim 7, further comprising a fluid passage formed between the outer and inner shafts for receiving a fluid.
 13. The bipolar electrosurgical debridement system of claim 12, further comprising: a fluid source fluidly connected to the fluid passage at the handle. 